Flexible binder post



A- MULLlKlN FLEXIBLE BINDER POST Filed Nov. 23, 1946 INVENTOR. BY

ATTORNEY Feb. 19, 1952 Patented Feb. 19, 1952 UNITED STATES PATENT OFFICE FLEXIBLE BINDER POST Alfred Mullikin, San Francisco, Calif.

Application November 23, 1946, Serial No. 711,963

This invention relates to loose leaf binders and more particularly to flexible binding posts therefor.

Among the objects of the invention is the provision of a resilient binding post for loose leaf binders that will permit the binder to open flat in use.

Another object is the provision of means for preventing the elongation of the binding posts beyond the predetermined capacity of the binder.

Another object is the prevention of lateral distortion of the spiral binding post in operation.

A further object is to avoid the necessity for providing hinge portions in the cover boards adjacent the binding posts.

Other objects and advantages will appear as the description progresses. In the specification and the accompanying drawings the invention is disclosed in its preferred form. But it is to be.

understood that it is not limited to this form because it may be embodied in modifications within the spirit of the invention as defined in the claims following the description.

In the one sheet of drawings:

Fig. l is a vertical section of a binder having this invention applied thereto and shown in full lines.

Fig. 2 is a vertical section of a binding post constructed in accordance with this invention.

In detail the structure shown in Fig. 2 comprises the resilient coil spring post I, preferably composed of hard metal wire spirally wound in close formation, without space between the coils, and cut to the desired overall length.

The binding screws 2, 3 have external threads matching the pitch of the helix of the coil post, but slightly larger in outside diameter so that the threads of the screw will wedge snugly into the respective ends of the post I, and prevent their dislodgment therefrom, except by manual withdrawal. These screws have overhanging curved heads 4, 5, with transverse screwdriver slots 5, I respectively.

These screws also have internally threaded axial holes therethrough, to receive the threaded ends 8, 9 of the flexible tie-wire II]. It is preferable to form these threaded ends on the wire by the thread rolling method, which forms an enlarged diameter of the threaded portion without reducing the gauge of the wire I0, and with-- out causing surface scores therein liable to cause breakage when flexed. The internal threads are the same pitch as the external threads, to prevent binding action. 1

In assembling the binder, as in Fig. 1, the

2 Claims. (01. 85-1) wire end 9 is inserted into the end of the screw 3 for about one-half its length. The screw 3 is then inserted into the end of the coil I and turned by a screwdriver in the slot 1, until the end of the coil abuts the underside of the head 5 and jams.

The ferrule I I having the flange I2 is then dropped over the coil I and against the head 5. The cover-board I3 has a hole therethrough fitting the ferrule I I. The loose leaves I4 similarly punctured are stacked on the cover I3 to the height of the binding post. The top cover board I5 having a hole therethrough is laid on top the sheets surrounding the coil post I.

The ferrule I6 is then pushed through the hole in the top cover-board and telescopes over the top end of the coil, with its flange I'I lying on top of the top cover-board.

The screw 2, having a countersunk center hole internally threaded, is entered into the upper end of the coil I and turned by a screwdriver in the slot until the center hole engages the threaded end 8 of the flexible tie wire III. The screw 2 is then turned until its underside binds against the flange I1 and compresses the leaves I4 surrounding the post between the top and bottom cover-boards I3, I5. The tie wire I0 prevents any elongation of the post I during and after assembly and in use. For freedom of operation the mass of leaves should not be compressed too compactly.

The invention is intended more particularly as a permanent binder, for that reason the posts are made of a predeterminedlength depending upon the thickness of the book desired. 'Lhese posts are inserted at intervals across the width of the cover and the thickness of the mass of leaves to give stability to the assembly. In general practice the wire used will range from 17 to 20 B & S gauge, more or less, according to the size and the mass of leaves to be bound.

If the covers such as I 3, I5 are of wood or other hard material the ferrules II, I6 may be omitted and the ends of the spring entered there in with the heads 4, 5 bearing against the covers, with or without an interposed-washer. The external threads at 2, 3, may also be omitted in lighter structures.

The invention operates substantially as follows: When fully assembled as in Fig. 1, the book is opened in the usual manner. This causes the post I and the tie-wire II) to bend backward in a true are until the outside covers I3, I5 will lie in a flat plane. The stack of leaves X will move forward in an are common with the arc of the post coils H), the series of loops forming the helix of the coil will move slightly relative to each other without opening any space between them on the longer are at the front of the coil, because of the non-extension of the flexible tie wire H] which bends in an are substantially concentric with the are formed at the rear side of the coil.

The closed structure of the coil walls extending slightly oblique or helically to the plane of the sheets ['4 also prevents them from entering the walls of the coil 1, in the open position of the book, since the leaves are perpendicular at all times to the axis of the coil. This is further assured by the burr that usually surrounds punched holes in paper sheets.

screws in :the opposite ends of said spring {and having external threads engaging the helix :pitch of :said spring and having iinternal :threads of substantially the same :pitch; and arsingle :relatively stiff but laterally flexible tie wire coaxial with said spring and having externally threaded ends engaging said internal threads in said binding screws respectively.

2. A flexible post in the class described, comprising a close wound helical spring; binding screws in the opposite ends of said spring and having external threads engaging the helix pitch of said spring and having internal threads of substantially the same pitch and heads overhanging the diameter of said spring, respectively; and a single relatively stiff but Flatjera'lly flexible tie wire coaxial with said spring and having externally threaded ends engaging said internal threads in said binding screws respectively; and ferrules surrounding the respective ends of said spring with annular flanges bearing beneath said overhanging -heiaA;ls--Of the said screws respectively.

ALFRED MULLIKIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,4745602 Miller Nov. '20, 1 923 FOREIGN PATENTS Number :Country Date 15559;? Greatz'Britain is. vAug. 15., i894 :of 11189.4 

